"I only found out later that he was taking money out of my account on the sly," Sharron told the Herald.
In total, he transferred $97,070 from his mother's bank account into his own.
Of that, he told Christchurch District Court that $20,000 was a "legitimate civil loan" for a house deposit and $19,240 was either transferred to a cash card his mother used or was put towards their flights to the UK. Sharron denies giving him permission to take that money too.
Billington pleaded guilty to a representative charge of unlawfully obtaining $57,830 by deception.
In October 2016, Judge David Saunders sentenced him to six months of supervision and three months of community detention.
At his sentencing, Billington told the judge that he had sold the car and boat and that he was able to pay the full amount back within a month. Judge Saunders ordered $57,830 to be paid within 28 days.
But 49-year-old Sharron hasn't received any money yet.
"I'm absolutely disgusted with this. I came back to the UK to start a new life and I can't even do that," Sharron said.
"I've lost absolutely everything. I have no home, no money, no nothing."
It's understood that Billington might be living and working in the Nelson area.
Although a warrant has been issued for Billington's arrest, both police and the Ministry of Justice say that without being given an address for Billington, they are unable to track him down.
Constable Aaron Campbell who has dealt with the case said that while he sympathised with the victim, he had done everything he could to help her receive the money owed to her.
A police spokesman added that as the Ministry of Justice was the agency responsible for collecting and enforcing reparation orders, enquiries should be forwarded to the ministry.
However, in documentation seen by the Herald, the courts say their hands are tied.
They say the only way to catch up with Billington is if he was to break the law, get pulled over by police in a traffic stop, or if he tried to leave the country.
"When an offender is actively avoiding the Ministry of Justice it can be very difficult to find them," says one letter to Sharron from a Collections Unit staff member.
Bryre Patchell, Ministry of Justice group manager for national service delivery, said the case remained active with the court's collections unit.
Collecting reparation was a priority for the court, Patchell said, and the court's fines and reparation enforcement system was "comprehensive".
"The court can issue orders requiring reparations to be deducted from wages, benefits and bank accounts, can seize property of a person who has not paid their reparations and have offenders arrested and brought back before a judge," he said.
"Unfortunately some circumstances can mean a victim receives low repayments or no repayments. These circumstances include when the offender has a low or no income, several people are owed money by the same offender, the offender is in prison or the offender cannot be found.
"In these circumstances, the court will keep trying to collect the reparations. It welcomes any information on the whereabouts of an offender so that it can try to locate them."